Ohaeles a



(no model.)

0; A. CHEEV ER'; Electric Speaking Telephone.

No 235,50s-.- Patented Dec. 14,1880.

N. PETERS. PHOTO-LITMOGRAPHEH, WASHINGTON, D CS PATENT OFFICE.

CHARLES A. OHEEVER, OF NEW YORK, N. Y.

ELECTRIC SPEAKING-TELEPHONE.

SPECIFICATIQN' forming part of Letters Patent No. 235,508, dated December 14, 1880. Application filed March 22, 1880. (NomodeL) To all tvhom it may concern:

Be it known thatI, CHARLES A. OHEEVER, a citizen of the United States, and a resident of the city, county, and State of New York,

have invented certain new and useful Improvements in Electric Speaking-Telephones,

' rent passes. The apparatus most generally used for producing such variations consists,

' broadly stated, of a vibrating transmitting-diaphragm and a carbon button, through which the current passes. Experience has demonstrated that it is better not to attach the conducting body permanently to the case of the telephone, but to mount it upon a yielding support allowing a certain amount of play. The well-known Blake transmitter, in which the conducting body is mounted on an adustable spring, is'a goodillustration of this last-mentioned forrnof apparatus. Experience has, however, demonstrated even this form of apparatus to beobjectionable, it being difficult to permanently adjust the tension of the spring properly, and a very slight variation of such tension is often sufficient to pre- 7 vent the proper working of the instrument.

My invention constitutes an improvement more particularly upon the apparatus shown in an application for Letters Patent of the United States 'filed' by Allen W. Rose, October 27, 1879, which shows two diaphragms substantially parallelzto each other, mounted on a suitable casing or support, with interposed conducting bodies, through which the circuit passes, betweenthem. The diaphragins are electrically insulated from their support, and are preferably rendered adjustable with relation to each other. My invention, however, can be applied to many of the well-known forms of battery-telephones other than the one'above mentioned.

' The subject-matter herein claimed consists of certain novel organizations or arrangements upon circuit of well-known instrumentalities,

which organizations are specified in the claims at the end of this specification.

The'acoompanying drawings show various organizations of apparatus, including a telephone, batteries, wires, and induction coils. Figure 1 shows both resistance-contacts as connected with the same pole of the battery, the interposed independent conductor being connected with the other pole, under which arrangement the battery-current passes to the central pin or interposed conductor, then divides and passes to the respective resistancecontacts. Fig. 2 shows a similar arrangement with two batteries in the circuit. Fig. 3 shows two batteries with the interposed independent conductor insulated and the connecting-wires so arranged that the current from one. battery passes through one contact-point to one side of the interposed'conductor, while the other passes to the other. Fig.4 represents asimilar arrangement with each set of wires connected with the primary circuit of a separate or independent induction-coil, the secondary circuits of which induction-coils are connected with each other. Fig. 5 represents a similar arrangement, except that the intermediate conductor is not divided or insulated, and consequently but a single connecting-wire is required.

It will be sufficient to indicate herein the respective parts, as their organization and op eration are well understood.

The line-wire, in this instance, constitutes the secondary circuit of an induction or Ruhmkorft' coil, N, the primary circuit of which is connected with a battery, b, the wires of which circuit connect with the carbon buttons or resistance-contacts a a on diaphragms A B, the current in all cases passing through an interposed independent conductor, F.

All the organizations shown operate advantageously, as they avoid the roughness of sound sometimes noticeable in telephones of this class-that is, one having but one contactpoint or conducting-pin. For instance, instruments like the well-known Blake transmitter are liable to have the continuity of their circuit broken by excessive vibrations of the diaphragm, instead of only varying the strength of the current, and thus by the breaks causing a snapping in the receiving-telephone and greatly confusing the articulation.

Under my organization it is impossible that both contacts should be simultaneously broken,

and consequently there will always be more or less current flowing through the primary circuit of the induction-coil, and breaks in the continuity of the current, such as hereinbefore referred to, will therefore be avoided.

I claim as of my own invention- 1. The combination, substantially as here inbefore set forth, of resistance-contacts, wires connecting them with the same pole of the battery, an independent interposed conductor connected with the other pole of the battery, an induction-coil, and the line-wire.

2. The combination,substantially as hereinbefore set forth, of resistance-contacts.wires connecting each resistance-contact with one pole of the battery, interposed divided contactrpoints insulated from each other, and each in electrical connection with its respective resistance-contact, a separate battery for each 20 contact-circuit, an induction-coil, and a linei In testimony whereof I have hereunto signed 3 5 my name this 19th day of March, 1880.

CHAS. A. OHEEVER. Witnesses:

G. R. WATERBURY, J. WALDEN. 

